Mechanical driving device



July 21, 1970 R GQUDIN ET AL MECHANICAL DRIVING DEVICE Filed July 1, 1968 FI-G.2

I INVENTOR. ROBERT GOUDIN BY JACQUES BU NEL United States Patent Int. Cl. Fie N28 US. Cl. 74-231 5 Claims ABSTRACT OF THE DISCLOSURE A mechanical driving device adapted for use with a belt drive. A support member is secured in a non-slip fashion around the teeth on the belt and the support is further provided with projecting knobs for drivingly engaging the perforations of an adjacently placed tape.

The invention relates to a mechanical driving device in the form of a driving belt.

Driving belts having projections are already known. The embodiments of these belts may be arranged in three main types.

A uniformly perforated metal tape provided with projections which are secured thereto by rivets.

A metal tape having rows of perforations in the transverse direction. A metal wire which constitutes a cylindrical coil is threaded through the holes of two adjacent rows; this coil constitutes the core of the projection which is formed in place.

Finally there is a flexible belt formed by a metal core which also forms part of the projections. The tape is specially manufactured for the particular use or purpose intended.

The materials for the manufacture ofthe projections usually are thermosetting resins, polymerisable plastics, rubber, and similar materials.

The object of the various constructions is to obtain a driving device without play and slippage. Play is particularly troublesome in those cases in which, a perforated paper tape or a system of toothed wheels is to be driven with precision. Slippage is troublesome since it prevents a suitable transmission of a movement. In addition it renders a higher tension on the transmission belt and hence requires a driving motor having a considerably larger power.

The play has been removed by using flexible tape and the slippage has been removed by using projections, but in the above mentioned constructions the combination of these two means resulted in belt or tapes the manufacture of which is complicated. Furthermore, the perforation of the tapes reduces its effective cross-section and must be produced with great precision so as to obtain a regular step size.

On the other hand flexible drive tapes are known, having transverse notches on the surface which prevent slippage of the tape on the pulleys.

It is the object of this invention to provide a flexible positive driving device, of simple construction, which will operate without play and without slippage and of an easy construction.

The mechanical driving device according to the invention has a flexible belt or tape, on one surface of which transverse teeth are provided by which the tape is driven, and on the other surface projections are provided for driving by the tape. It is characterized in that the said projections are secured on supporting members which are held on the said tape by connection lugs folded about the edge of the tape and extending on either side of a tooth.

On the surface opposite to the teeth, the said tape comprises transverse notches, the edges of each of the supports rests on the top of two adjacent notches.

In the event the securing of the projections on the supports involves an extra thickening, said extra thickening is located in a notch.

In order that the invention may be readily carried into effect, one embodiment thereof will now be described in greater detail, by way of example, with reference to the accompanying drawing, in which FIG. 1 is a longitudinal cross-sectional view of the tape according to the invention,

FIG. 2 shows a cross-sectional view taken on the line aa of FIG. 1.

According to one embodiment the driving device consists of a belt or tape of the type known by the trade name Synchroflex the profile of which is shown in FIG. 1. This belt has a core of steel wires, which are embedded in a flexible polymer. The rectangular teeth on the lower side are for driving the belt and avoiding slippage while the oppositely located triangular notches give the belt a larger flexibility.

The projections which are used for driving a perforated paper tape have the shape of knobs 1 and may be manufactured of any solid or semisolid material. Each of these knobs is secured to a support 2 of metal which has the form of a strongly flattened U (FIG. 2). The two limbs of the U are cut in such manner that only two lugs 3 remains (FIGS. 1 and 2) which are bent on either side of a rectangular tooth.

Since securing a knob onto the U-part causes a thickening thereof, the sawtooth profile is used for compensation by causing the edges of the support 2 to bear on the triangular teeth.

Since the pitch of the rectangular teeth is 6.35 mm., a division of the knobs over the belt is obtained every other tooth which corresponds to the standardized centre line distance of the perforations of the driven paper, namely 12.7 mm. The use is not restricted to a pitch of 6.35 mm.; a tape having a different pitch which corresponds either to the pitch of the perforations of the paper, or to a multiple of the pitch may alternatively be used.

An advantage of the use of such supports is the possibility of using the sides thereof for guiding the tape.

For the driving device according to the invention, any tape or belt may be used which has a profile the parts of which alternately project and recess. The supports and projections may consist of one piece, if desired, which may consist of metal.

What is claimed is:

1. A mechanical driving device having a flexible tape on one surface of which transverse teeth are provided by which it is driven and projections on the other surface by which it drives, characterized in that the said projections are secured on supports which are secured to the said tape by connection lugs which are folded around the edge of the tape and extend on either side of a tooth.

2. A device as claimed in claim 1, characterized in that the said tape comprises transverse notches on the surface opposite to the teeth, the edges of the support bearing on the tops of two adjacent notches.

3. A mechanical driving device for use with a flexible belt, having transverse teeth on a first surface thereof for engagement with belt driving means, and comprising a support member secured to the belt and around said teeth, the support member extending over a second surface of the belt, and a knob member aflixed to the sup- Patented July 21, 1970 port member and projecting outwardly from the second surface for slip-free positive driving.

4. A mechanical driving device as claimed in claim 3 wherein the second surface of the belt defines notches therein, and the support member bears against the tops of said notches.

5. A mechanical driving device as claimed in claim 4 wherein the support member has a flattened U shape, and the limbs of the U are bent around the opposite sides of the teeth.

References Cited UNITED STATES PATENTS JAMES A. WONG, Primary Examiner 

